The latter, I believe, depends on how you want metadefs to be loaded into the database when existing metadefs exist. If users are adding their own and on upgrade we load the new metadefs from upstream, then we may cause problems for users who've created their own.
Perhaps we should only provide a way to load metadefs, not do it by default?
For what it's worth we'll want to use
glance-manage db_load_metadefs /usr/local/ etc/metadefs {overwrite, merge,prefer_ new,}
The latter, I believe, depends on how you want metadefs to be loaded into the database when existing metadefs exist. If users are adding their own and on upgrade we load the new metadefs from upstream, then we may cause problems for users who've created their own.
Perhaps we should only provide a way to load metadefs, not do it by default?